U.S. patent application number 12/478353 was filed with the patent office on 2009-12-17 for apparatus and method for hydrolysis of cellulosic material in a multi-step process to produce c5 and c6 sugars using a single vessel.
This patent application is currently assigned to ANDRITZ INC.. Invention is credited to Thomas Pschorn, Namhee Shin, C. Bertil Stromberg.
Application Number | 20090308383 12/478353 |
Document ID | / |
Family ID | 41413621 |
Filed Date | 2009-12-17 |
United States Patent
Application |
20090308383 |
Kind Code |
A1 |
Shin; Namhee ; et
al. |
December 17, 2009 |
APPARATUS AND METHOD FOR HYDROLYSIS OF CELLULOSIC MATERIAL IN A
MULTI-STEP PROCESS TO PRODUCE C5 AND C6 SUGARS USING A SINGLE
VESSEL
Abstract
A system and method for extracting C.sub.5 sugars including
pentose and/or C.sub.6 sugars including hexose from a slurry of
cellulosic material comprising cellulose, water, and optionally
acid.
Inventors: |
Shin; Namhee; (Clifton Park,
NY) ; Stromberg; C. Bertil; (Diamond Point, NY)
; Pschorn; Thomas; (Lennoxville, CA) |
Correspondence
Address: |
NIXON & VANDERHYE, PC
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON
VA
22203
US
|
Assignee: |
ANDRITZ INC.
Glens Falls
NY
|
Family ID: |
41413621 |
Appl. No.: |
12/478353 |
Filed: |
June 4, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61060299 |
Jun 10, 2008 |
|
|
|
Current U.S.
Class: |
127/9 ;
127/44 |
Current CPC
Class: |
C13K 1/02 20130101; C13K
11/00 20130101 |
Class at
Publication: |
127/9 ;
127/44 |
International
Class: |
C13D 1/14 20060101
C13D001/14; C13D 3/00 20060101 C13D003/00 |
Claims
1. A system for extracting C.sub.5 sugars including pentose or
C.sub.6 sugars including hexose from a slurry of cellulosic
material comprising cellulose, water, and optionally acid, the
apparatus comprising: (i) an inlet adapted to receive the slurry at
a top of a vessel; (ii) a first stage in which the slurry is
exposed to a first temperature between 130.degree. C. and
190.degree. C. for a first period of time ranging between 10
minutes and 120 minutes; (iii) a first extraction screen and first
line that is adapted to remove a first liquid comprising C.sub.5
sugars including pentose or C.sub.6 sugars including hexose or
hemicellulose from the slurry; (iv) a counter-current wash zone in
which the slurry is exposed to a second temperature between
100.degree. C. and 170.degree. C. for a second period of time
ranging between 30 minutes and 120 minutes, wherein a
counter-current wash zone includes a first recycle loop through
which water is added to the slurry; (v) a second stage in which the
slurry is exposed to a third temperature between 150.degree. C. and
190.degree. C. for a third period of time ranging between 30
minutes and 240 minutes, wherein the liquid in the second stage is
prevented from re-entering the counter-current wash zone, and
wherein the second stage comprises a second recycle loop through
which the temperature or pH of the second stage is adjusted; and
(vi) an exit stream adapted to receive a soup-like consistency of
cellulosic material after treatment in the second stage, wherein
the exit stream exits the bottom of the vessel.
2. The system according to claim 1 further comprising a
pass-through zone between the wash zone and the second stage
preventing material from the second stage from entering the wash
zone.
3. The system according to claim 1, wherein the system comprises a
single vessel.
4. The system according to claim 1, wherein the second temperature
is between 140.degree. C. and 160.degree. C.
5. The system according to claim 1, wherein the slurry comprises
acid and the first temperature is between 130.degree. C. and
170.degree. C.
6. The system according to claim 1, wherein the slurry does not
comprise acid and the first temperature is between 170.degree. C.
and 190.degree. C.
7. The system according to claim 1, wherein the second temperature
is between 140.degree. C. and 160.degree. C.
8. The system according to claim 1, wherein the third temperature
is between 180.degree. C. and 190.degree. C.
9. A method for extracting C.sub.5 sugars including pentose or
C.sub.6 sugars including hexose from a slurry of cellulosic
material comprising cellulose, water, and optionally acid, the
method comprising the steps of: feeding the slurry of cellulosic
material comprising cellulose, water, and optionally acid to a
first stage via an inlet at a top of a vessel; exposing the slurry
in the first stage to a first temperature between 130.degree. C.
and 190.degree. C. for a first period of time ranging between 10
minutes and 120 minutes; extracting liquid comprising pentose or
hexose from the slurry in the first stage; passing the slurry to a
counter-current wash stage; feeding water to the counter-current
wash stage via a first recycle loop; exposing the slurry in the
counter-current wash stage to a second temperature between
100.degree. C. and 170.degree. C. for a second period of time
ranging between 30 minutes and 120 minutes; passing the material
through a pass-through zone; passing the slurry to a second stage;
exposing the slurry in the second stage to a third temperature
between 150.degree. C. and 190.degree. C. for a third period of
time ranging between 30 minutes and 240 minutes while lowering the
pH, wherein the slurry in the second stage obtains a soup-like
consistency; feeding acid or base to the second stage via a second
recycle loop, wherein the second recycle loop passes through a heat
exchanger; and removing the slurry from the vessel.
11. The method according to claim 10, wherein the pass-through zone
prevents material from the second stage from entering the wash
zone.
12. The method according to claim 10, wherein the second
temperature is between 140.degree. C. and 160.degree. C.
13. The method according to claim 10, wherein the slurry comprises
acid and the first temperature is between 130.degree. C. and
170.degree. C.
14. The method according to claim 10, wherein the slurry does not
comprise acid and the first temperature is between 170.degree. C.
and 190.degree. C.
15. The method according to claim 10, wherein the second
temperature is between 140.degree. C. and 160.degree. C.
16. The method according to claim 10, wherein the third temperature
is between 180.degree. C. and 190.degree. C.
Description
RELATED APPLICATION
[0001] This application claims the benefit of priority to U.S.
Provisional Patent Application No. 61/060,299 filed Jun. 10, 2008,
the entirety of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a method and an apparatus for
hydrolysis treatment of cellulosic fiber material.
[0003] In conventional systems, wood chips (or other cellulosic or
fiber material) can undergo hydrolysis in a single vessel prior to
treatment or cooking in a digester, such as described in U.S. Pat.
Nos. 3,380,883 and 3,413,189. In such systems, hydrolysis occurs
under acidic conditions in the slurry of wood chips, e.g.,
cellulosic material, passing through a top section of the vessel
with the continued treatment of cooking in lower sections of the
vessel followed by washing in the bottom of the vessel. In the
upper region of the vessel, hydrolysate, e.g., C.sub.5 and C.sub.6
sugars such as pentose and hexose and other hemicellulose, is
extracted from wood chips and the hydrolysate is recovered.
[0004] Hydrolysis occurs throughout the upper region of the vessel
by the introduction of steam, acid and/or water in a concurrent
flow in the upper region. In the lower region of the vessel, the
cellulosic material is cooked and washed and is subsequently
discharged as pulp from the vessel.
[0005] It is generally believed that performing the hydrolysis at a
high temperature may produce the greatest volume of desired sugars.
But high temperature treatment of wood or other cellulosic material
may cause operational problems for the reaction vessel. For
example, the treatment (hydrolysis) of cellulosic material at
temperatures over 170.degree. C. may cause the lignin to dissolve
and may lead to an accumulation of the lignin in the vessel,
especially on the internal surfaces. To avoid this lignin
dissolving and accumulation in the vessel, the vessels may be
operated at lower temperatures and for longer time. This may
require a larger vessel resulting in a higher capital
investment.
[0006] Other methods of hydrolyzing cellulosic material are
described in U.S. application Ser. Nos. 12/114,856 (U.S. Pat. App.
Pub. No. 2008/0302492) and Ser. No. 12/114,881 (U.S. Pat. App. Pub.
No. 2008/0295981).
[0007] In certain aspects, the present invention may relate to
hydrolyzing cellulosic material while minimizing any undesirable
effects with respect to lignin (e.g., accumulation within the
reaction vessel).
BRIEF DESCRIPTION OF THE INVENTION
[0008] The purpose of the invention is to dissolve the vast
majority of hemicellulose and the majority of the cellulose present
in the feed material, thereby chemically disintegrating the
structure of the lignin cellulosic feed stock particles, such that
the material will form a soup-like material.
[0009] In an aspect, an embodiment generally relates to an
apparatus for extracting C.sub.5 (pentose) and/or C.sub.6 (hexose)
from a slurry of cellulosic material comprising cellulose, water,
and optionally acid, the apparatus comprising (i) an inlet adapted
to receive the slurry at a top of a vessel; (ii) a first stage in
which the slurry is exposed to a temperature between 130.degree. C.
and 190.degree. C. for a period of time ranging between 10 minutes
and 120 minutes, (iii) a first extraction screen and line that
remove liquid containing C.sub.5 (pentose) and/or C.sub.6 (hexose
and hemicellulose) from the slurry, (iv) a counter-current wash
zone in which the slurry is exposed to a temperature between
100.degree. C. and 170.degree. C. for a period of time ranging
between 30 minutes and 120 minutes, wherein the counter-current
wash zone includes a first recycle loop in which water may be added
to the slurry; (v) a second stage in which the slurry is exposed to
a temperature between 150.degree. C. and 190.degree. C. for a
period of time ranging between 30 minutes and 240 minutes, wherein
the liquid in the second stage may not re-enter the counter-current
wash zone, and wherein the second stage includes a second recycle
loop through which the temperature and/or pH of the second stage
may be adjusted; and (vi) an exit stream adapted to receive a
soup-like consistency of cellulosic material after treatment in the
second stage, wherein the exit stream exits the bottom of the
vessel. To ensure no material from the second stage enters the
counter-current wash zone, a pass-through zone may be located
physically between the wash zone and the second stage. This
pass-through zone allows the material to merely move through the
zone.
[0010] In an aspect, an embodiment generally relates to a method
for extracting C.sub.5 (pentose) and/or C.sub.6 (hexose and
hemicellulose) from a slurry of cellulosic material comprising
cellulose, water, and optionally acid, the method comprising the
steps of: feeding the slurry of cellulosic material comprising
cellulose, water, and optionally acid to a first stage via an inlet
at a top of a vessel; exposing the slurry in the first stage to a
temperature between 130.degree. C. and 190.degree. C. for a period
of time ranging between 10 minutes and 120 minutes; extracting
liquid comprising pentose and/or hexose from the slurry in the
first stage; feeding the slurry to a counter-current wash stage;
feeding water to a counter-current wash stage via a first recycle
loop; exposing the slurry in a counter-current wash stage to a
temperature between 100.degree. C. and 170.degree. C. for a period
of time ranging between 30 minutes and 120 minutes; passing the
material through a pass-through zone; feeding the slurry to a
second stage; exposing the slurry in the second stage to a
temperature between 150.degree. C. and 190.degree. C. for a period
of time ranging between 30 minutes and 240 minutes while lowering
the pH, wherein the slurry in the second stage obtains a soup-like
consistency; feeding acid and/or base to the second stage via a
second recycle loop, wherein the second recycle loop passes through
a heat exchanger; removing the slurry from the.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is an illustrative schematic diagram of a reactor
vessel in accordance with an embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0012] In certain aspects, the present invention generally relates
to a method and apparatus to dissolve C.sub.5 and C.sub.6 sugars
from cellulosic material. Preferably, the traditional Kraft cooking
process is not used to produce dissolved C.sub.5 sugars. C.sub.5
sugars include, for example, xylose, arabinose and other pentoses.
C.sub.6 sugars include, for example, glucose, mannose, other
hexoses and other hemicellulose compounds.
[0013] In an aspect, the cellulosic material may be hydrolyzed in a
multiple-step process within a single vessel. Cellulosic material
may be fed to the top of a vessel (e.g., a cylindrical vessel) in a
slurry. The cellulosic slurry may be fed using a pump, hydrostatic
pressure, or any other method of delivering the slurry to a top of
a vessel.
[0014] The pH of the slurry containing cellulosic material may be
between 0 and 7. In certain embodiments, the slurry may contain
water or a mixture of water and acid to achieve the desired pH. In
certain embodiments, the slurry of material upon entering the
vessel the material is heated to a temperature of between
130.degree. C. and 190.degree. C. (and all subranges therebetween)
and has a liquid to wood ratio of between 1 to 1 and 1 to 10 (and
all subranges therebetween).
[0015] In certain embodiments, there may be a hydrolysis stage with
a short or very short duration or residence time where the
temperature is over 170.degree. C. This short time period may
facilitate dissolving C.sub.5 sugars while inhibiting dissolving
lignin. In such a hydrolysis stage, it is believed that the linkage
or bond between the hemicellulose and the lignin is broken (thus
yielding the C.sub.5 sugars). It is believed that the lignin does
not dissolve because the location of the lignin in the cellulosic
material may require a longer treatment or exposure time to
dissolve the lignin.
[0016] According to certain embodiments, the cellulosic material is
held in a first stage of hydrolysis for a short time and at a high
temperature. In certain embodiments, the time period may last
between 10 and 120 minutes (and all subranges therebetween). In
certain embodiments, the temperature may be between 130 and
190.degree. C. (and all subranges therebetween) and preferably
above 170.degree. C. if acid is not added to the slurry. If acid is
added to the slurry, the temperature in this first stage may be
lowered, but would be above 130.degree. C. In this stage, it is
believed that the C.sub.5 sugars are formed by breaking the linkage
between the hemicellulose and lignin. After the short, high
temperature hydrolysis stage, liquid containing the C.sub.5 sugars
is extracted and sent to further process units for processing, such
as separation, purification, etc.
[0017] Following the extraction of the C.sub.5 sugar rich stream
produced from the first hydrolysis stage, a counter current wash
zone may be provided. In this wash zone, relatively cool water
(e.g., below 170.degree. C.) may added to a circulation loop to
allow for cooling of the cellulosic material. In this
counter-current wash stage the hot cellulosic material may be
cooled to facilitate diffusion out of the dissolved hemicellulose,
thus leaving primarily the lignin and cellulose in the mass of
cellulosic material. This counter-current wash may occur for a
period between 30 minutes and 2 hours (and all subranges
therebetween) and at temperature between 100.degree. C. and
170.degree. C. (and all subranges therebetween), preferably at a
temperature of 140.degree. C. to 160.degree. C. (and all subranges
therebetween).
[0018] Following a counter-current wash stage may be a section of
the vessel where the cellulosic material passes through without the
addition of liquid. A second hydrolysis stage is located below the
pass through section of the vessel. In preferred embodiments,
essentially no liquid from the second hydrolysis stage is permitted
to flow upward through the pass-through section of the vessel.
[0019] A circulation loop may be located at the end of the
pass-through section of the vessel. This loop may consist of a
screen to facilitate the removal of liquid from the vessel. If
desired, acid may be added to lower the pH of the liquid, and/or a
heater may be provided to allow for the increase in the temperature
to above 180.degree. C. (and preferably 180.degree. C. to
190.degree. C.) if necessary.
[0020] In the second hydrolysis stage, the cellulosic material may
partially or fully dissolve. The residence time or duration of the
second stage may be between 30 minutes and 4 hours (and all
subranges therebetween). At this point, there may exist a
continuous breakdown of the cellulosic material to such a point
that the material is a "soup" or colloidal suspension of lignin,
carbohydrates, and dissolved fibers. In this "soup," biomass
particles may not be visible.
[0021] This process may facilitate the control of the biomass in
the top part of the vessel independent of the bottom section of the
vessel and independent of what is removed from the bottom of the
vessel. Due to the "soup" consistency in the bottom, the top of the
vessel may be easier to control.
[0022] The "soup" may then be discharged from the bottom of the
vessel for processing downstream, where it may be separated into
its various components (e.g., valuable products).
[0023] FIG. 1 schematically illustrates an embodiment including a
single vessel 100. A slurry of cellulosic material enters the top
of vessel 100 via line 110. In preferred embodiments, the
cellulosic slurry includes chips and/or pulp, water, and optionally
acid. In other embodiments, further additives may be present in the
cellulosic slurry, e.g., to facilitate the extraction of C.sub.5
and/or C.sub.6 sugars from the cellulosic material.
[0024] After entering the vessel 100, the cellulosic slurry enters
a first stage 120 where it is exposed to a temperature between
130.degree. C. to 190.degree. C. for a period of time between 30 to
120 minutes. After this stage, a liquid containing C.sub.5 sugars
and/or C.sub.6 sugars is extracted via screen 122 and line 124.
[0025] The hot cellulosic slurry then enters a counter-current wash
zone 130, where it dwells for a period of time between 30 minutes
and 2 hours at a temperature between 100.degree. C. to 170.degree.
C. Counter-current wash zone also includes a recycle loop
comprising lines 134 and 140, pump 138, and line 136 (through which
relatively cool water may be added to the recycle loop so as to
cool the cellulosic material in the counter-current wash zone).
[0026] After this counter-current wash zone, the cellulosic
material enters a second hydrolysis stage 142. Preferably, no
liquid or material from the second stage 142 enters counter-current
wash zone 130. This second stage 142 includes a recycle loop
comprising lines 146 and 154, pump 150, heat exchanger 152 (though
which the temperature of the second stage may be adjusted), and
line 148 (through which acid/base may be added to adjust the pH of
the second stage). The temperature of the second stage may be above
150.degree. C. (e.g., above 170.degree. C. or between 180.degree.
C. and 190.degree. C.). The residence time of the second stage may
be between 30 minutes and 240 minutes. The cellulosic material may
have a soup-like consistency and may be removed from vessel 100
through optional stage 156 and line 158 and exposed to further
downstream processing. Preferably, the sole extraction of dissolved
C.sub.5 (pentose) and C.sub.6 (hexose) in liquid occurs once: after
the first hydrolysis stage.
[0027] While the invention has been described in connection with
what is presently considered to be the most practical and preferred
embodiment, it is to be understood that the invention is not to be
limited to the disclosed embodiment, but on the contrary, is
intended to cover various modifications and equivalent arrangements
included within the spirit and scope of the appended claims.
* * * * *